This invention relates to a voltage controlled oscillator and, in particular, to a voltage controlled oscillator operable over a wide range of frequencies.
A band switching voltage controlled oscillator is described in U.S. Pat. No. 5,739,730 given to Rotzoll. The band switching of Rotzoll relies on diodes such as varactor diodes being added selectively to a tuning circuit by switches.
In the above-mentioned voltage controlled oscillator, switching is carried out of the components in and out of the tuning circuit operating at radio frequency. This results in the introduction of unwelcome circuit parasitics. Also in applications for which it is important to minimize equipment volume and the number of components used, improvements over the prior art are necessary.